Case Studies

Crinipellis australis

Mushrooms of the species Crinipellis australis are coloured brown and have caps about a centimetre in diameter atop stems about two centimetres long. Around the time of World War 1 specimens of this species were collected in Adelaide and from two sites in Sydney and those specimens are stored at the Adelaide herbarium. Initially they had been identified as a different species of Crinipellis but a new study of these specimens showed that they were distinct from the other species in the genus and so in 1997 the new species Crinipellis australis was formally published. At that time the three early collections were still the only known collections of the species but in the early summer of 2004/2005 the species turned up in abundance in Canberra. The fact that the species was found in Canberra was of course interesting in itself, for this was an area distant from each of the early collection sites. In addition, the abundance of Canberra specimens from a variety of sites gave some very useful information about the ecology of this species. In a search through unidentified herbarium collections I found one more group of Crinipellis australis specimens from Canberra, collected in June of 1991.

The CanberraCrinipellis australis sites varied from a small area of Themeda grassland, little disturbed by weeds or human activity, to quite the opposite - a weedy paddock with a long history of grazing, though not constantly stocked. In between there were moderately disturbed patches of grassland and grassy woodland. The constant in all these was the presence of grasses. The original report about the species noted that the mushrooms grew “on the ground, often attached to buried grass stems” and the Canberra evidence bears this out. Even in areas where twig or leaf litter was abundant no Crinipellis australis mushrooms were found on such substrates. Moreover, the species seemed especially partial to Themeda. If Themeda were present the majority of Crinipellis mushrooms would commonly grow on Themeda, even if it was not the dominant grass species in an area. In contrast to the other native grasses the Themeda tussocks often contain a sizeable proportion of dead material, which presumably provides a good volume of food for the fungus. During the 2004/2005 summer a friend and I looked for Crinipellis also in grassy areas where there were no native grasses but never found any Crinipellis in those areas, even though some were quite close to areas with Crinipellis. All of this suggests that the fungus is a specialist species of native grassland or grassy woodlands and that it may still be found over a wide area of at least south-east mainland Australia in a wide variety of grassy habitats. However the grassland and grassy woodland habitats of south-eastern mainland Australia are subject to various threats. Many such habitats are in areas ideal for pastoral use or housing development and most have already disappeared or been greatly modified since European settlement. Therefore Crinipellis australis may well be widespread but with a very patchy distribution.

The pre-2000 Crinipellis australis collections were collected in autumn/early winter, a time when many mushrooms do appear. Why was there an abundance of Crinipellis australis in the early summer of 2004/2005? That early summer was only a little warmer than average, but much wetter. For example, at Canberra airport the November rainfall was 85.5 mm (the average for November being 63.4) and the December fall was 72.4 (average 52.5). This suggests that the fungus is able quickly to exploit good rain. Such an ability would be of considerable benefit, especially in areas without dense tree or shrub cover, such as grasslands and open woodlands. In such habitats the ground is exposed to the full force of the drying effects of sun or wind so the benefits of rainfall would at times be short-lived.

Another characteristic that would help Crinipellis australis cope with exposed habitats is that when the mushrooms dry they shrivel but don't decay or collapse. Unlike most mushrooms, if re-wetted they will swell out and resume sporing. Several mushrooms, either collected dry or allowed to dry naturally after collection, gave copious spore prints after rehydration. Canberra receives variable amounts of rain at irregular intervals during the warmer months. Often a short period of cool, rainy days is followed by warm to hot and dry days. It is common to see small mushrooms and puffballs appear, develop a little and then abort during the hot days. It is also not too unusual to see that happen in exposed areas during autumn, whenever drying winds are severe. It is likely that similar observations could be made in many other areas of south-eastern Australia. In such cases the resources put into mushroom development have been wasted. With Crinipellis australis the revival ability would guard against such a waste of resources and allow the fungus to take advantage of several short rainy periods that are separated by dry periods. The hairy surfaces would presumably help the fungus make the most of any available moisture. They would help trap moisture, for example by acting as condensation points for overnight dew or for fine misting rain. The hairs may also slow down the loss of water from the sporocarp surface. The species therefore seems well adapted to life in grasslands and open woodlands.